CHAPTER 1
INTRODUCTION
1.1
Background of study problem
Criminal cases involving explosives are crimes often used by criminals in
order to destruct and vanish the evidence. The murder of a Mongolian citizen in
Malaysia that occurred in October 2006 would be the best example. The high profile
has led to how the victim has been exploded by C-4 in the jungle. Fragments of
skeleton and hairs evidence were part of the investigation. Apart from the studies of
deoxyribonucleic acid (DNA) analysis in hair, the type of explosive can be
determined by employing a chemical analysis.
Forensic scientists have extensively researched on drug analysis on hair. Drug
detection in hair has been a motivating research by scientist during the last 15 years.
In 1954, barbiturate was the first organic drug detectable in guinea-pig hair (Gaillard
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and Pepin, 1997). The illegal drugs and the presence of heavy metal and other
chemical in the body can be detected by performing hair analysis. The exposure of
chemical vapor to hairs sample has been conducted by some researchers in the mid
1900’s (Oxley et al., 2005). In addition, hair provides information of historical
record of chemical exposure of surrounding.
Explosives appear in massive kinetic energy that can produce an explosion.
There are several factors that can initiate the explosive to explode such as liberation
of heat and development of sudden pressure. The analysis of explosive has been
divided into two types namely a pre blast analysis and post blast analysis (Johns et
al., 2007).
The residues of after post blasts explosives usually are invisible to human
naked eyes, particularly when the residues are deposited in layers of debris material.
The explosives can be determined in either of qualitative and quantitative by doing
an analysis on the debris material collected close to point of explosion. The
analytical techniques for analyzing the origin of explosives depend on the type of
explosives, as to whether it is an organic or inorganic material. It is difficult to
identify the type of explosives at the crime scene. Therefore, selecting on the right
analytical technique without damaging the evidence is a requirement because of
limited evidence amount of post blast residues. Thus, the advantages, limitation and
the sensitivity range of various techniques for detection of the explosives must be
considered first.
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1.2
Problem Statement
After an explosion, the vicinity around the blast seat is often strewed with
post blast fragments containing explosive residues. Human head hairs of victims or
spectators are also likely to sorb unreacted or remaining explosive that were used for
the explosion. Due to an increase number of human head hairs encountered as post
blast samples, it was therefore necessary to undertake a study to develop method for
the analysis of explosive residues in human hair.
1.3
Objectives of Study
The objectives of this study are:
i.
To investigate the absorption level of explosive in hair based on:
a. Distance from bom seat with the hair sample
b. The natural and dyed hair
ii.
To study all possible factor that effect explosive adsorption into hair
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1.4
Scope of the Study
The scope of this study involved the use of human head hairs of natural and
dyed color will be utilized. Explosion residues in human head sample are detected by
employing GC-ECD.
1.4
Significance of the Study
The results of this study will be made available to forensic chemists in
government laboratories such as Department of Chemistry Malaysia. The developed
method will hopefully be useful and can be proposed as a standard method for
explosive analysis in hair samples. Levels of explosive residues in hairs will also be
of assistance to police investigations for the purpose of post blast identification
(PBI).